Families are moving to outer boroughs such as Bexley, south-east London.
Photograph: Martin Godwin for the Guardian

Tens of thousands of poor families have left inner London in the past five years, creating “social cleansing on a vast scale” and leaving large parts of the capital as the preserve of the rich, figures suggest.

The figures portray a mass shift of poorer families from inner London just when the government has introduced a raft of changes to the welfare system.

Although there is no definite link between welfare reforms and the reduction in free school meal claimants, Sadiq Khan, the prospective London mayoral candidate who obtained the figures, said government policies were creating an increasingly segregated city.

“This data shows that the government’s policies on welfare and housing have caused social cleansing in London on a vast scale,” said Khan. “Families have been driven out of large parts of the city ... this is not the kind of London I grew up in or want my daughters to live in.”

Betsy Dillner, director of housing campaign group Generation Rent, said runaway rents and a shortage of social housing were “uprooting families from inner London and stopping others from having children in the first place.”

“The housing crisis is not only disrupting education for children who are forced to move away from their schools; it pushes workers further from their workplaces and that puts pressure on businesses and public services. The creation of areas that serve only the rich are damaging communities, undermining the economy and destroying social mobility.”

The figures show that while there has been a 3% drop in those eligible for free school meals across England, four inner London boroughs have seen a decline of 25% or more. Across inner London as a whole there was an average fall of 16%.

Khan said some of those families appear to have moved to outer boroughs where, although there was an overall fall in the numbers entitled to free school meals, several areas saw a substantial increase. In Merton there was a 19% rise, Bexley 15%, and Croydon 11%. Khan said other families had moved out of the capital altogether.

“I’ve met countless families who have been ripped away from their family and friends, with children forced to travel an hour and a half just to get to school,” said Khan.

“Frankly we’re being socially cleansed,” said the MP for Islington North at a hustings event. “The rent goes up, the benefit cap doesn’t meet the rent. That means [people are] either forced to go hungry or move away from their families and the lives they’ve built.”

Tony Travers, a professor at the London School of Economics, said the flight of poorer families from the capital was, in part, a consequence of government policy.

“I would be surprised if government policies like the bedroom tax and the benefits cap had not had a displacement effect and that is what we appear to be seeing here.”

Travers said these policies had strengthened an ongoing trend that, since the 1990s, has seen inner London become more affluent and more expensive.

“This phenomenon is one that any future mayor of London would want to know much more about because if inner London is being hollowed out it would have big implications and would be something to take action on.”

Asked about the declining number of children eligible for free school meals in inner London and claims that this indicated mass social cleansing, the Department for Work and Pensions said: “Our welfare reforms ensure the long-term sustainability of the welfare system while also providing an £80bn safety net for those who need it. Families in work make decisions on where to live based on what they can afford every day, and it’s fair that households on benefits face those same decisions.”

Khan, who was shadow minister for London, said if he was elected mayor he would build more affordable homes and introduce a living London wage, linking rent levels to income.

“I’ll do everything I can to stop the government’s plans to reduce the welfare cap and sell off more affordable family homes. We must make sure that this city remains affordable to all those who want to live here”